Pump used in dredging systems operating with compressed air

ABSTRACT

An improvement in the pumps, used in the dredging systems and operating with compressed air, is disclosed, wherein foreign materials, tending to interfere with the operation of the inlet valve and at times to clog the supply pipe of the compressed air, are prevented from entering into the said pipes, by means of an inlet pipe for the dredged material the discharge opening of which is not flushed with the bottom of the pump casing and the closure member for the said discharge opening is positioned outside of the inlet pipe and is axially displaced with respect to the inlet pipe and above the same.

United States Patent {191 Faldi 1 1 Feb. 12, 1974 [54] PUMP USED IN DREDGING SYSTEMS FOREIGN PATENTS OR APPLICATIONS OPERATING WITH COMPRESSED AIR 2,002,190 8/1970 Germany 417/125 [76] Inventor: Giovanni Faldi, Via Forese Donatu, 549,716 l2/l942 Great Britain 417/118 27, Firenze, Italy Primary Examiner-William L. Freeh [22] Flled' 1972 Assistant Examiner-Richard E. Gluck I21] Appl. No.: 228,006 Attorney, Agent, or FirmKarl W. Flocks [30] Foreign Application Priority Data 1 ABSTRACT Mar. 16, 1971 Italy 2I85I A/71 'mpmvemcm "U P used m systems and operatmg wIth compressed an, 15 dIs- 521 US. Cl 417/118, 37/58, 417/503 f whereinforeign mterialse ending P 51 Int. Cl F04f l/06, E02f 3/88 Wlth 'letvalve and F [58] Field of Search... 417/118, 126, I22, I21, 123, 310% the supply P'P 9 the mpressed all, are pre- 417H25, 432, 503 431; 137/605; 37/56, 58 vented fro m entermg Into the and pIpes, by n 1eans of an Inlet pIpe for the dredged materlal the dlscharge [56] References Cited opening of wire: no:l flushed wit: thfe bolgtom ojfhe pump casIng n e osure mem er or e saI 15- UNITED STATESPATENTS charge opening is positioned outside of the inlet pipe 1,326,321 l2/19l9 Callahan 417/11 d is axially displaced with respect to the inlet pipe 3,552,884 1/1971 Faldi 417/122 and above the'sama 1,766,382 6/1930 Hardie et a1. 417/121 2,266,126 12/1941 Malsbary et a1. 417/503 X 3 Claims, lDrawing Figure A) 9 l I r" I.

. .l 8 (I I, 8 14 t I 1 I 14 PATENTEB 3974 PUMP USED IN DREDGING SYSTEMS OPERATING WITH COMPRESSED AIR There are known dredging systems operating with compressed air comprising a submerged pump resting on or dragged along the bottom to be dredged, consisting of one or more casings furnished each with an inlet valve and a valve for discharging the dredged material, said casings being connected through fixed piping and through a fixed cycling distributor to a source of compressed air situated at a distance from the pump and having the purpose of periodically emptying the dredged material from each of the casings, and through other piping to the reflow header of the dredged material.

In the above type of dredging systems certain disadavantages have had to be recognized, due especially to the present structure and operation of the pump in which materials can enter or tend to enter which interfere with the normal operation of the inlet valve and which tend at times to penetrate into the supply pipe of the compressed air with the danger of impeding the normal distribution of the air itself.

The subject of the present invention is an improved type of pump for dredging systems with which the above disadvantages are eliminated and the operation of the entire system improved.

One of the improvements is characterized by the fact that in each casing the seat of the inlet valve, instead of being situated on a level with the bottom of the casing as is normally done, is located at a moderate height above the bottom itself in which the opening occurs for entrance of the material, through means of a pipe which may reach a height above the bottom equal to about one-third of the total height of the pump casing. Another characteristic consists in the fact that the plug element for the closing andopening of the valve, ball or cap, moves in an axial direction in respect to the valve seat along guides placed above the seat and therefore outside the inlet pipe without interfering with the discharge opening of the same.

Thus is obtained the advantage of not creating any obstacle to the entrance of the dredged material, of assuring the perfect closing of the valve, of making it possible at the bottom of the pump casing to collect-foreign objects, iron, stones or pieces of a substantial size that could obstruct the entrance of the discharge pipe, and finally of making easily accessible, from above, the valve and the pumping chamber (through means of a suitable hole closed by flanges in the top wall of the casing) for the contingency of possible repairs or overhauling.

Another improvement is characterized by the fact that for each pump casing, on the inside of the inlet pipe, briefly described above, and more precisely below the inlet valve, there is an opening for connection of a pipe for the supply of clear water which, through suitable piping and regulatable throttling valve, can be made to flow from the control station. This improvement is for the purpose of being able to regulate easily the percentage of solids (sand, gravel and similar material) which mixed with the water enter the pump casing during the intake phase. Each pipe, for supplying clear water to the individual casings of the pump, can be provided with a single fast operated gate valve or more suitably with an one-way flap valve, so as to permit the clear water to be passed from the main pipe to the inlet pipe of the pump casing, but to prevent any intercommunication between each intake pipe and the others.

In the case of a pump with multiple casings, the clearwater supply pipes each comprising the above mentioned one-way check or gate valve, of the individual casings are connected to a single pipe which is regulated through a single throttling valve controlled manually or through any other well known system.

A further improvement is characterized by the fact that in each of the pump casings and in conjunction with the inlet opening of the compressed-air pipe there is situated a valve with inverted seat and floating movable closing element (ball or cap). This valve is constructed with a cage which guides a ball (or a cap) which is movable and which, as the pump fills with liquid, rises until it blocks the inverted valve seat, preventing the sandy or muddy mixture from entering with violence into the air pipes and from possibly passing through the distributor, when the compressed air is being discharged into the atmosphere, damaging the distributor itself.

A preferred arrangement is illustrated in the attached drawing which shows the schematic view, in elevation and partially in section, of a pump constructed with two casings.

The pump shown is constructed with two casings 1. Each of said casings is furnished with an inlet pipe 2 for the dredged material, which in accordance with the invention terminates at about one-third of the height of the casing l and whose opening forming a valve seat 22 is closed and opened cyclically from above through means of a cap 3 guided freely by guides 4 fixed to a flange 5 which is closed by an inspection window 6. For the cyclical operation of the valve cap 3 actuating means are foreseen of types well-known in the art and not illustrated here for sake of clarity.

The references 7, 8, 9 indicate the pump discharge pipe, the corresponding valve and the connection to the header 10 from which branches off the overflow pipe of the dredged material.

. According to the invention the pump is connected to a supply pipe of clear water which through a throttling valve 1 l, regulatable manually or with any other known system, enters a manifold 12 from which branch off as many pipes 13 as there are pump casings, said pipes, each comprising an one-way check valve 18, opening into the inlet pipes 2 near their inlet end and below the valve with cap 3, to make it possible, as already stated, to dilute more or less the mixture of the dredged material which is to enter the pump casing, without having any intercommunication between the several inlet pipes. Still according to the invention the inlet and outlet pipe 14 for the compressed air leads into the interior of the respective casing through a valve with floating ball (or cap) 15 housed and guided in a cage 16 and furnished with an inverted seat 17. Said valve prevents the sandy or muddy mixture from entering pipe 14 and possibly reaching the distributor during the discharging of the compressed air into the atmosphere.

I claim:

1. An improved submersible dredging pump of the compressed air type adaptable to resting on or being dragged along the bottom of a body of liquid to be dredged, said pump comprising one or more casings into which dredged material may be received, each of said casings being provided with an inlet pipe and inlet valve assembly and an outlet pipe and outlet valve assembly for dredged material, said inlet pipe having an opening for receiving dredged material, said inlet valve assembly being situated above said inlet pipe and including a seat portion disposed at a height equal to about one-third the total height of the casing above an interior bottom surface of the casing associated there- 7 with, said outlet pipe extending below the upper extremity of said inlet pipe, each of said casings additionally including compressed air means communicating with the interior thereof 7 to facilitate discharge of dredged material from the respective casing associated therewith, said seat portion being formed on said inlet pipe at its upper extremity and being closed and opened cyclically by a downwardly pointing plug element disposed above said seat portion and movable in a direction axial to said seat portion along guide means disposed above and externally of said seat portion, and said inlet pipe including an additional opening outside said casing which opening is in communication with pipe means for supplying clear water from a manifold having a regulative throttling valve, said clear water pipe means has a gate valve therein; whereby material to be dredged may be caused to enter said casing by being entrained in water, to impinge against said plug element at its under surface and directed toward said bottom surface of said casing with finer particles such as sand settling out in said casing and not being entrained and carried into said outlet pipe and downstream thereof to thereafter impair proper functioning of a system associated therewith, and said throttling valve being operative to control and adjust the volume of water of clear water added to material passing into said inlet pipe.

2. An improved pump as recited in claim 1 wherein said guide means and said plug element are accessible from the top of the respective casing through opening means which are normally closed by a removable cover.

3. An improved pump as recited in claim 1 wherein said compressed air means cooperating with each of said casings includes a valve assembly with an inverted valve seat member and a movable element of floating material which cooperate to prevent entry of muddy mixture into the compressed air means during discharge of the dredged material from said casing. 

1. An improved submersible dredging pump of the compressed air type adaptable to resting on or being dragged along the bottom of a body of liquid to be dredged, said pump comprising one or more casings into which dredged material may be received, each of said casings being provided with an inlet pipe and inlet valve assembly and an outlet pipe and outlet valve assembly for dredged mateRial, said inlet pipe having an opening for receiving dredged material, said inlet valve assembly being situated above said inlet pipe and including a seat portion disposed at a height equal to about one-third the total height of the casing above an interior bottom surface of the casing associated therewith, said outlet pipe extending below the upper extremity of said inlet pipe, each of said casings additionally including compressed air means communicating with the interior thereof to facilitate discharge of dredged material from the respective casing associated therewith, said seat portion being formed on said inlet pipe at its upper extremity and being closed and opened cyclically by a downwardly pointing plug element disposed above said seat portion and movable in a direction axial to said seat portion along guide means disposed above and externally of said seat portion, and said inlet pipe including an additional opening outside said casing which opening is in communication with pipe means for supplying clear water from a manifold having a regulative throttling valve, said clear water pipe means has a gate valve therein; whereby material to be dredged may be caused to enter said casing by being entrained in water, to impinge against said plug element at its under surface and directed toward said bottom surface of said casing with finer particles such as sand settling out in said casing and not being entrained and carried into said outlet pipe and downstream thereof to thereafter impair proper functioning of a system associated therewith, and said throttling valve being operative to control and adjust the volume of water of clear water added to material passing into said inlet pipe.
 2. An improved pump as recited in claim 1 wherein said guide means and said plug element are accessible from the top of the respective casing through opening means which are normally closed by a removable cover.
 3. An improved pump as recited in claim 1 wherein said compressed air means cooperating with each of said casings includes a valve assembly with an inverted valve seat member and a movable element of floating material which cooperate to prevent entry of muddy mixture into the compressed air means during discharge of the dredged material from said casing. 